Snowmobile air box assembly

ABSTRACT

The present invention is directed to an air box assembly for a snowmobile. The air box assembly is capable of being positioned frontward of the snowmobile engine, relative to a front end of the snowmobile. In this position, throttle noise being dampened by the air box assembly is further removed from an operator of the snowmobile sitting in an operator position on the snowmobile.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an air box assembly for a vehicle, andmore specifically relates to an air box assembly for a snowmobile thatincludes air-silencing capabilities.

2. Related Art

Air box assemblies for snowmobiles have been in use for decades. Air boxassemblies serve at least two purposes. First, the air box assemblyprovides an air intake to the throttle body assembly of the engine.Typically, the air box assembly filters incoming air from an air sourceas part of providing air intake to the throttle body assembly. Second,the air box assembly provides air-silencing capabilities by dampeningthrottle noise produced by the throttle body assembly that travels backto the air box assembly.

Known snowmobile air box assemblies are typically positioned rearward ofthe engine relative to a front end of the snowmobile. The air boxassembly, in this rearward position, is also typically positionedfrontward of the fuel tank of the snowmobile and adjacent the steeringcolumn. In this position, the air box assembly is just underneath andfrontward of an operator sitting in an operator position of thesnowmobile. Despite the noise dampening performed by an air box assemblyin this position, the vehicle operator is typically exposed to aconsiderable amount of throttle noise due to the closeness of the airbox assembly to the operator.

SUMMARY OF THE INVENTION

The present invention is directed to an air box assembly for asnowmobile. The air box assembly is capable of being positionedfrontward of the snowmobile engine, relative to a front end of thesnowmobile. In this position, throttle noise being dampened by the airbox assembly is further removed from an operator of the snowmobilesitting in a driver position on the snowmobile.

In an alternative embodiment, an air box of the air box assemblyincludes a top portion in fluid communication with the snowmobilethrottle body assembly, and a bottom portion that is capable of actingas a skid plate of the snowmobile. The bottom portion may be part ofmolded one piece structure that also forms a nose cone and bumper forthe front of the snowmobile, and also may include a mount or hinge forthe hood of the snowmobile.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one example of an air box assembly ofthe present invention in fluid communication with an engine throttlebody assembly and mounted to a snowmobile chassis;

FIG. 2 is a close up view of the air box assembly mounting shown in FIG.1;

FIG. 3 is a perspective view of the air box assembly shown in FIG. 1;

FIG. 4 is a side view of the air box assembly shown in FIG. 1;

FIG. 5 is a front view of the air box assembly shown in FIG. 1;

FIG. 6 is a top view of the air box assembly shown in FIG. 1;

FIG. 7 is a side view of another example of an air box assembly of thepresent invention that utilizes a skid plate of the snowmobile as abottom portion of the air box assembly;

FIGS. 8 and 9 are bottom and top perspective views of a molded skidplate—nose cone—front bumper piece that is useful in an embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to an air box assembly for a snowmobilethat is positioned frontward of the snowmobile engine, relative to afront end of the snowmobile. The air box assembly includes an air inletin fluid communication with an air source and an air inlet/outlet portin fluid communication with a throttle body assembly of the snowmobile.In some embodiments, the air box assembly further includes a flexibletube having a first end secured to the air inlet/outlet port and asecond end secured to the throttle body assembly to provide fluidcommunication there between.

FIGS. 1 and 2 illustrate a portion of a snowmobile assembly 10 thatincludes an air box assembly 12, a throttle body assembly 14, an engine16, and a chassis 18. The chassis 18 includes a front portion 30, arearward portion 32, and an operator position 34. The engine 16 ispositioned in the chassis in a “lay down” orientation such thatcylinders 40, 42 of the engine are angled relative to a vertical linethat extends through a drive axis 44 of the engine. The engine includesexhaust ports 46, 48 and air inlets 50, 52. The throttle body assembly14 includes first and second portions 60, 62 that are secured to the airinlets 50, 52, respectively, to provide fluid communication therebetween.

Air box assembly 12 is shown in further detail in FIGS. 3-6, andincludes a top side 70, a bottom side 72, a front side 74, and a rearside 76. Air box assembly 12 also includes an air inlet 80, and aflexible air channel 82 extending from the rear side 76 to air outlets84, 86. Air outlets 84, 86 are secured to the first and second portions60, 62 of throttle body assembly 14 to create fluid communicationbetween air box 12, throttle body 14, and engine 16.

The bottom side 72 of air box assembly 12 is configured for mounting tochassis 18. In an alternative embodiment of an air box assembly 112shown in FIG. 7, the bottom side 172 of the air box assembly 112 iscapable of acting as a skid plate 190 or belly pan of the snowmobile.Such a configuration would reduce the net weight and overall cost of theair box assembly for the snowmobile. In an embodiment illustrated inFIGS. 8 and 9, the bottom side of the air box assembly is part of a onepiece component that provides a skid plate, nose cone and front bumperfor the snowmobile. The nose cone may be adapted for mounting of thehood of the snowmobile, for example through the use of an aperturedprotrusion that can accept a hinge pin. This component may be formed ofa suitable plastic material such as high density polypropylene. Otherpolymer materials or metals can be used, or combinations of materialscan be used, e.g. a polymeric shell on a metal frame piece or the use ofmetal for a support framework for hollow ribs of the component.

Air box assemblies 12 and 112 each are positioned frontward of engine 16relative to front end 30 of chassis 18. With the air box assemblypositioned forward on the chassis, throttle noise generated by throttleassembly 14 is dampened at a location on the snowmobile further from anoperator and other passengers of the snowmobile positioned in operatorposition 32. Thus, the arrangement of the air box assembly frontward ofthe engine provided by the present invention reduces throttle noise forthe snowmobile operator and passengers.

A further advantage of positioning the air box assembly frontward ratherthan rearward on the chassis (i.e., adjacent the fuel tank) is thatthere is more space available for fuel tank capacity. Increased fueltank capacity reduces the frequency at which the fuel tank must berefilled.

A still further advantage of positioning the air box assembly frontwardof the snowmobile engine is that the air box is able to draw from asource of air that is less affected by heat being generated by theengine. Typically, cooler air being fed to the engine through thethrottle body assembly equates to improved engine performance. Thus, bypositioning the air box assembly frontward of the engine, the source ofair for the air box assembly may also be positioned more frontward onthe snowmobile and removed from heat being generated by the snowmobileengine. In addition, during operation of the snowmobile snow can enterthe engine compartment through openings in the hood, where it isvaporized due to the heat of the operating engine. Positioning the airbox assembly frontward of the engine reduces the exposure of the airintake system to water vapor from the snow, increasing the intake ofcold clean air.

Another advantage of positioning the air box assembly forward of theengine is that there is more room in the chassis for rotating the engineinto a “lay down” position and moving the engine into a lower, morerearward position on the chassis than a typical engine configuration. A“lay down” engine orientation lowers the center of gravity for thesnowmobile and moves the center of gravity to a more rearward position,thus promoting greater stability for the snowmobile.

The above specification, examples and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended.

1. A snowmobile, comprising: an engine comprising a throttle bodyassembly; and an air silencer in fluid communication with the throttlebody assembly and positioned frontward of the engine.
 2. The snowmobileof claim 1, wherein the air silencer comprises a first portion in fluidcommunication with an air source, and a second portion in fluidcommunication with the throttle body assembly.
 3. The snowmobile ofclaim 1 wherein the air silencer is configured with multiple internalchambers, the chambers being capable of dampening throttle noisegenerated by the throttle body assembly.
 4. The snowmobile of claim 1wherein the air silencer comprises a top wall, a bottom wall, and a rearwall, the top wall comprising an air inlet, the bottom wall capable ofbeing secured to a chassis of the vehicle, and the rear wall comprisingan air inlet/outlet in fluid communication with the throttle bodyassembly.
 5. An air silencer configured for use with a snowmobileengine, comprising: a top portion configured to be in fluidcommunication with a throttle body of the engine; and a bottom portioncapable of acting as a skid plate of the vehicle.
 6. The air silencer ofclaim 1, wherein the bottom portion is part of a component that providesa skid plate and nose cone for a snowmobile.
 7. The air silencer ofclaim 6, wherein the component further provides a front bumper for asnowmobile.
 8. A snowmobile comprising the air silencer of claim
 5. 9.(canceled)
 10. The method of claim 9, wherein the air box assemblycomprises a top portion in fluid communication with an air source. 11.The method of claim 10, wherein the air box assembly comprises a rearportion having an air inlet/outlet port in fluid communication with thethrottle body assembly.
 12. The method of claim 11, wherein the air boxassembly comprises a flexible tube having a first end secured to the airinlet/outlet of the rear portion, and a second end secured to thethrottle body assembly.
 13. (canceled)
 14. An air silencer configuredfor use with a snowmobile engine, comprising: a top portion configuredto be in fluid communication with an air source; and a rear portionconfigured to be in fluid communication with a throttle body of theengine; whereby the air silencer is capable of being positionedfrontward of the engine relative to a front end of the snowmobile.